Hoping for advice on specific M-mount lenses with helicoid adapter (which are ok, and which are not)

Started 11 months ago | Discussions thread
dbm305 Senior Member • Posts: 1,744
Re: Hoping for advice mount lenses with helicoid adapter (which are ok, and which are not)

Rol Lei Nut wrote:

dbm305 wrote:

Any lens can be used on a helicoid, including floating element lenses, if you calibrate the helicoid for infinity at lens hard stop. That's a reason for using the latest Hawk adapter that allows this.

That's fine, as long as you don't extend the helicoid (which pretty much defeats its purpose)....

The thought is that even if you extend the helicoid the results won't be any worse than a lens without a floating element, and likely better, since with the lens set to mfd the fle will be in the correct position for the closest native focus. Sure, you won't get optimized close correction as you extend the helicoid, but you won't get that with a unit focusing lens either. The important thing is to make sure that the correction element isn't set for some distance further than mfd (in fact just setting the lens to mfd would probably be fine if extending the helicoid, infinity calibration is more important for longer distances

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